The Eastern Victoria region MP, who is the leader of the Nationals in the upper house, had already said he would step down at the November election after 25 years in the Victorian parliament to devote more time to his family.

On Wednesday he released a statement saying it was the right time to step aside.

"It has been an honour and a privilege to be both an MP and a minister in the Victorian parliament," he said.

"Now is the right time for me to step aside and provide an opportunity for the next generation of Nationals to showcase their talents and take this great government into the next election."

Mr Hall will deliver his valedictory speech to the parliament on Thursday, his spokeswoman said.

The new candidate for his seat will be elected following a Nationals pre-selection meeting on Saturday.

His portfolio responsibilities will be up for grabs in a cabinet reshuffle by Premier Denis Napthine expected in the next fortnight.

Nationals ministers, including Sports Minister Hugh Delahunty and Aboriginal Affairs and Local Government Minister Jeanette Powell, have already announced they won't recontest their seats of Lowan and Shepparton respectively at the state election.